Final answer:
An NDC number indicates registration with the FDA but does not guarantee FDA approval. The NDC is a product identifier, while FDA approval is obtained through a rigorous process of clinical trials and safety evaluations.
Step-by-step explanation:
When a product has an NDC (National Drug Code) number, it signifies that the manufacturer has registered the drug product with the FDA (Food and Drug Administration). However, an NDC number does not automatically imply FDA approval. The FDA reviews New Drug Applications (NDA) extensively before granting approval. This process includes significant testing and trials to ensure the drug's safety and efficacy. After submitting an Investigational New Drug (IND) application, researchers can commence clinical trials, and ultimately, drugs that pass these phases and are deemed safe and effective are granted FDA approval. An NDC is rather a universal product identifier for human drugs in the United States.